Thank you gentlemen for all your inputs. I looked into pro amps and "high-end" amps and decided to take the path of least resistance to my wallet. I decided to upgrade/modify my own Adcom GFA 555 II for less than half of all the other options. I am having the following modifications done.

1. Replace a 675 VA input transformer with two 1KVA, making it dual mono.

2. Replace 16 old, 150 watts/180 volts output tansistors with (still) 16 new ones rated 250watts/250volts.

3. Replace four 15k uF capacitor to 33k uF ones.

4. Replace 25Amp rectifiers with 50Amp ones.

Along with these main changes, some minor ones will be done as well -- drivers are being updated and bypass caps are being added near the output for supposedly "faster recharging."

I don't know if the modified amp will drive the VMPS woofers well or not, but I am hoping that this least expensive path will significantly improve the bass response of these speakers. My main concern is whether the existing heat sink will be able to handle the increased capacity, but I am hoping that driving only the bass (2 10" cones and a passive radiator each speaker) won't heat up the amp very much. Plus I don't blast music (mainly orchestral, operatic, jazz and blue grass music) and Adcom GFA 555 II is as big as Outlaw 770 and has impressive fins on the back.

Thanks again for the advices.